Here's a place where I can post my thoughts on new papers, provide updates on my projects, and post info that will eventually be on my website The Theropod Database - http://theropoddatabase.com/ . It will center on theropods, but may delve into other topics as well such as phylogenetics.

Other diagnoses- Pickering (DML, 2002) listed several features as differing from Metriacanthosaurus parkeri. Of these, the straighter dorsal ilial margin and broadly exposed medial wall of the brevis shelf are seen in Eustreptospondylus, while the long ischial peduncle is also present in "Szechuanosaurus" zigongensis. The lower ilial blade are seen in both. Contra Pickering, the pubic peduncle is not noticably longer nor the subpreacetabular notch more open than in Metriacanthosaurus.

Comments- Lydekker (1888) referred a metatarsal III (BMNH R413) from the Chipping Norton Formation to Megalosaurus bucklandi. Gardiner (1937, 1938) and Reynolds (1938) reported large theropod remains from two quarries in the Chipping Norton Limestone Formation, which Reynolds (1939) described and referred to Megalosaurus. Pickering (1995) credited the name Metriacanthosaurus reynoldsi to Welles, Powell and Pickering in his 1995 unpublished bibliographic manuscript. It was later used in the comparative section of another unpublished manuscript (Welles and Pickering, 1999). This paper was largely extracted from the European megalosaur manuscript Welles and Powell worked on in the 1970s but never published, specifically the Megalosaurus redescription section. Pickering intends to publish an updated version of the megalosaur manuscript as Mutanda Dinosaurologica, and has posted small excerpts including the diagnosis of Metriacanthosaurus "reynoldsi" online (DML, 2002). In any case, the name is a nomen nudum as Pickering didn't follow ICZN Article 7 Recommendation 7a, Article 8a or Recommendation 8A. The 1999 paper shows his new taxon to be based on all the Chipping Norton theropod material from both quarries, as well as BMNH R413, scapula OUM J.29800 and a few other elements. Day and Barrett (2004) believed both their Megalosaurus femoral morphotypes A and B were present in the sample- SDM 44.23 (Q in the figure below) as morphotype B and SDM 44.24 as morphotype A. Benson (2009, 2010) referred the New Park Quarry material to Megalosaurus bucklandii based on the close resemblence of maxilla SDM 44.1 (A) to Taynton Limestone specimens and an M. bucklandii autapomorphy in sacrum SDM 44.4 (G), while other elements were provisionally referred as there is no evidence of more than one taxon in the quarry. These additional elements are- maxilla BMNH R8303 (B), anterior dentary BMNH R8304 (D), partial dentary BMNH R8305 (C), proximal ischium BMNH R9668, proximal caudal vertebrae BMNH R9672-9673 (H), partial anterior cervical vertebra BMNH R9674 (E), mid caudal vertebrae BMNH R9675-9676 (J, K?), proximal caudal vertebra BMNH R9677 (I), mid caudal vertebra SDM 44.5 (L), coracoids SDM 44.14-15 (M), humerus SDM 44.18 (N), femur SDM 44.24 (P) and distal metatarsal IV 44.25. BMNH R413 and OUM J.29800 were also referred to M. bucklandii based on autapomorphies. Finally, Benson (2010) referred two specimens from Oakham Quarry to M. bucklandii based on autapomorphies (ischium SDM 44.20 [O] and metatarsal III BMNH R9665 [R]), but refrained from referring additional elements from this quarry as he notes some "can be referred to a second, unnamed taxon (R. B. J. Benson, unpubl. data)." This near certainly refers to "reynoldsi", whose intended holotype is an ilium from Oakham Quarry (SDM 44.19). Further study by Benson and/or Pickering may clarify the identity of the other Oakham Quarry elements. The material Welles and Pickering referred to "reynoldsi" is here provisionally retained in the species, as none has been usefully described in the published literature.

Megalosaurus bucklandii material referred to "Metriacanthosaurus" "reynoldsi" by Welles and Pickering (1999). Not to scale. For specimen numbers, see list above. Taken from Benson (2010), except F, K and M from Reynolds (1939) and P and Q from Benson (2009).

The identity of SDM 44.19 is difficult to determine from the published illustration, since many useful ilial characters would only be visible in medial or ventral views. However, it is a tetanurine based on the lack of a strong crest between the supracetabular crest and brevis fossa, and is not a coelurosaur based on the large ischial peduncle and widely exposed brevis fossa in lateral view. It differs from Megalosaurus and Metriacanthosaurus in many of the same ways- anteroposteriorly narrow pubic peduncle; broad medial wall to the acetabulum, especially posteriorly; longer ischial peduncle; broad esposure of medial wall of the brevis fossa; low ilial blade. It is more similar to Metriacanthosaurus in the wide subpreacetabular notch, and anteroposteriorly wide ischial peduncle, but shares a series of short vertical ridges above the acetabulum with Megalosaurus (albeit more pronounced). Pickering's (DML, 2002) only ilial character for Metriacanthosaurus is "ilium + ischium fused", which isn't true of M. parkeri or "reynoldsi." Thus is seems whatever "reynoldsi" is, there's no reason to refer it to Metriacanthosaurus. A greater resemblence is seen to Eustreptospondylus, which shares the narrow pubic peduncle, broad esposure of medial wall of the brevis fossa, and low ilial blade. Another similar ilium is that of "Szechuanosaurus" zigongensis, which shares the broad medial wall to the acetabulum, longer ischial peduncle, and low ilial blade. Which of these two taxa it is more closely related to will require study of the specimen itself and additional specimens from Oakham Quarry. For now it is best placed either in basal Tetanurae or Eustreptospondylinae.

The illustrated Oakham tooth (BMNH or SDM colls) is short (height/FABL 1.66) and moderately recuved with perpendicular serrations on at least the apical half of the distal carina. Only light longitudinal striations are indicated on the enamel. At least one of the scapulae (SDM 44.16 and 44.17) is unfused to the coracoid, though it is unknown if these were from Oakham Quarry, or merely from New Park Quarry and unreferred by Benson to Megalosaurus.

Day and Barrett, 2004. Material Referred to Megalosaurus (Dinosauria: Theropoda) from the Middle Jurassic of Stonesfield, Oxfordshire, England: one taxon or two? Proceedings of the Geologists' Association. 115, 359-366.
Benson, 2009. An assessment of variability in theropod dinosaur remains from the Bathonian (Middle Jurassic) of Stonesfield and New Park Quarry, UK and taxonomic implications for Megalosaurus bucklandii and Iliosuchus incognitus. Palaeontology. 52(4), 857-877.

Benson, 2010. A description of Megalosaurus bucklandii (Dinosauria: Theropoda) from the Bathonian of the UK and the relationships of Middle Jurassic theropods. Zoological Journal of the Linnean Society. DOI 10.1111/j.1096-3642.2009.00569.x

DIAGNOSIS: Megalosauridae with sacral 4 longer ventrally than dorsally. The hypodigm indicates a Metriacanthosaurus with an illium having a more horizontal crest; the anterior blade is lower; the posterior blade is also lower, but begins much higher above the base of the peduncle, with a much greater area exposed below the spine; the public peduncle is longer; the ischial peduncle is much longer, the notch more open.

Most of your comments above, while interesting, are hampered by the fact that I have before me the original 1972 photographs + detailed illustrations of each specimen. The mss. devotes 2 1/2 pages of descriptive analyses to SDM 44.19, e.g.

Compared with Metriacanthosaurus parkeri OUM J12144 (A. Walker 1964, fig. 16e), which is damaged, the length between notches is slightly greater; the crest is more nearly horizontal, especially caudally. The height at the pubic peduncle is much higher above the base of the peduncle. The spine is lower, but is much higher above the blade. The public peduncle is longer, the notch similar. The acetabulum is higher and longer, its medial arch much lower. The ischial peduncle is much longer, the notch higher and even more open. Although there are obvious differents between them, SDM 44.19 is more like OUM J12144 than other taxa.

Compared with Eustreptospondylus OUM J13558, it is nearly twice as large, 300 vs. 165 mm between the notches. The height above the pubic peduncle is much greater than the internotch distance. The anterior blade is missing in both, as is the posterior blade in SDM 44.19. The cranial notch is more open. The base of the spine originates higher above the acetabulum, thus revealing more of the lower part of the posterior blade. The pubic peduncle is longer, its craniodistal end eroded. The acetabulum is higher, especially cranially, and its medial border is very much lower. The ischial peduncle is blunter.

Compared with the largest ilium of M. bucklandii OUM J13560 (A. Walker 1964, fig. 16d), SDM 44.19 is even larger, 300 vs. 285 mm between the notches. The crest is straight. The anterior blade is 200 vs. 183 mm high. The posterior blade originates higher, and has a more steeply dipping ventral edge. The spine is about the same height, but originates much higher, its ventral edge dipping cranially vs. caudally. The pubic peduncle is much longer cranially, the notch wider. The acetabulum has a similar best crest, but is lower (216 vs. 270 mm), its medial border much lower. The ischial peduncle is longer and recurved distally, the notch is even more open.

Needless to say, the hypodigm is Metriacanthosaurus. I can understand the frustration workers have, especially when they rely either upon Benson (who plunders Sam's original mss. without attribution) or Day & Barrett. Just because they state specimens are Megalosaurus does not mean they are Megalosaurus.

Thanks for the fine compendium of info, Stephan. I'll update my website entry accordingly for when I upload it. I don't suppose you could send me your equivalent list for Megalosaurus bucklandii? I have several specimens noted whose provenance and reference history I do not know.

Okay, after reading your comments I've revised a few element referrals. I agree you have the advantage of possessing the 1972 MS, and have changed my entry to reflect the anteroventrally eroded pubic peduncle. Yet I note we agree on how SDM 44.19 compares to M. parkeri and Eustreptospondylus. Ignoring size (as the Eustreptospondylus holotype is a subadult), the "height above the pubic peduncle is much greater than the internotch distance" and pubic peduncle longer in Megalosaurus too, so these don't indicate SDM 44.19 is Metriacanthosaurus. "The base of the spine originates higher above the acetabulum, thus revealing more of the lower part of the posterior blade" and "The acetabulum is higher, especially cranially, and its medial border is very much lower" are just as different between SDM 44.19 and parkeri. This leaves only the wider subpreacetabular notch (which isn't that much narrower in Eustreptospondylus) and blunt ischial peduncle as potentially uniting SDM 44.19 and parkeri. To me this does not substantially overcome the resemblence between the broadly exposed brevis fossae in SDM 44.19 and Eustreptospondylus. So my question is twofold- do you have any other Metriacanthosaurus synapomorphies in SDM 44.19, and have you compared it to "Szechuanosaurus" zigongensis, which seems more similar to it than parkeri (except the narrow subpreacetabular notch)?

SDM 44.19 (S. Reynolds 1939, fig. 8). The Reynolds figure is not especially useful, and I shall be using in Mutanda Dinosaurologica the magnificent illustration Sam provided me.

This is a large ilium, 300 mm between the notches, 380 mm high above the pubic peduncle x 216 mm high above the notch. Both blades are broken, leaving only the central body. The crest is nearly straight. The pubic peduncle is stout, with a straight pubic facet. The ischial peduncle is short and rounded. The spine begins far from the acetabulum, and high above the posterior blade, so a wide band of the latter is exposed below the spine. The acetabular crest is highly (144 mm) arched. The cranial notch is wide open.

Comparison with other taxa are above.

Compared with Allosaurus fragilis USNM 4734 (Gilmore 1920B, pl. 10) the differences are much the same as from Megalosaurus bucklandii OUM J13560. The crest is straighter, the blade lower, especially cranially. The anterior blade slops up more steeply from a wider cranial notch. The pubic peduncle is shorter. The ischial peduncle is ventrally thicker, the notch higher. The posterior blade originates higher above the peduncle, while the higher base of the spine exposes much more of the posterior blade. The acetabular crest forms a high arch vs. slanting cranioventrally. The medial border of the acetabulum is much lower.

Another point is that the partial left ischium SDM 44.20 has a caudally convex shaft, the distal end enlarged, but not expanded into the foot as in Metriacanthosaurus parkeri OUM J12144. SDM 44.21, a distal left ischium, 394 mm long, the distal end 111 x 64 mm, and although the caudodistal corner is broken away, very little is missing, probably less than 10 mm. The slight distal expansion, as in SDM 44.20, contrasts with OUM J12144, where the foot is ca. 180 mm long, and with Megalosaurus bucklandii OUM J13565 (Buckland 1824A, pl. 44 figs. 3-4) where the foot is 127 mm. However, on the basis of similarities to other elements of the hypodigm, Sam Welles believed Metriacanthosaurus reynoldsi is Metriacanthosaurus, vs. erecting a 'Megalosaurus' reynoldsi.

Another taxon is Metriacanthosaurus huxleyi, a name reserved in Mutanda Dinosaurologica for a homologous diagnostic hypodigm should this be found.Jurassic, Bathonian, Sharp's Hill Formation, Workhouse Quarry, Chipping Norton, Oxfordshire.Proposed type: BMNH R283, right ilium.

This is a Metriacanthosaurus with an ilium having pronounced buttresses, a high anterior blade with nearly horizontal ventral edge. The spine is very high caudally, the acetabular crest continues onto the ischial peduncle. The ischial peduncle is massive with a nearly vertical caudal edge.Compared with Metriacanthosaurus parkeri OUM J12144 (von Huene 1926B, fig. 49; A. Walker 1964, fig. 16e), which is poorly preserved, the two are different, 584 mm long vs. 712, height above the pubic peduncle 278 vs. 436 mm, H:L index 48 vs. 61. The buttresses on the blade are much stronger. The anterior blade is lower. The posterior blade has a more horizontal dorsal edge, its ventral edge much steeper. The spine has a horizontal ventral edge. The pubic peduncle is shorter, the notch narrower. The acetabular crest arches down onto the ischial peduncle, and the peduncle is ventrally thicker and has a vertical cranial edge, so that the notch is much wider. Although these differences are distinct, the shortness of BMNH R283 and the great height of its anterior blade clearly places BMNH R283 within Metriacanthosaurus and NOT Megalosaurus (contra Benson 2010B:885).Compared with Metriacanthosaurus brevis BMNH 31811 (R. Owen 1857A text), it is 584 x 278 vs. 640 x 393 mm, H:L index 48 vs. 61.Compared with Megalosaurus bucklandii BMNH R1100 (R. Owen 1857A, pl. 6), it is 585 vs. 757 mm long. The buttresses on the blade are much more pronounced. The anterior blade is much higher, its ventral edge aligned with that of the spine vs. dipping steeply cranially. The posterior blade has its ventral edge dipping steeply cranially. It originates a little higher on the peduncle, ending in a point beyond the spine. The spine is higher. The pubic peduncle is shorter, with a horizontal ventral edge. The acetabular crest is continuous down the ischial peduncle, lacking the notch above the peduncle. This peduncle is more massive, its caudal face vertical vs. recurved distally. The caudal notch is wider.STEPHAN PICKERING / Chofetz Chayim ben-AvrahamThe Dinosaur Fractals Project